High-speed relay



July 10, 1945. B, v. HOARD 2,379,905

HIGH SPEED RELAY Filed Sept. l, 1942 www Patented July 1o, 1945 UNlTED STATES PATENT I OFFICE HIGH- SPEED RELAY Bert V. Board, Portland, Oreg., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application september 1, 1942, serial No. 456,901

23 Claims.

My invention relates to high-speed alternating- 'current relays such as are used in the protection of electrical transmission systems, and for other purposes.

An object of my invention is to provide a new type of induction-disk or induction-cylinder relay in which practically all of the available surface of the induction-element is covered, with airgapseparation, by the pole faces of a. magnetic statorstructure which extends substantially all the way around a complete circle. By means of my new construction, or principles of construction, I am enabled to obtain many important advantages, including higher speed, a larger ratio of useful torque to rotor-inertia, increased sensitivity, low space-requirements, comparative freedom from stray-current torques or unwanted ,torques of any kind, increased range of low-voltage operation, a saturated iron magnetic circuit for the currentresponsive torque, freedom from vibration and rattle, uniform torque at all positions of the relay, freedom of interference from stray fields,

ease of inspection with respect to dirt, substantial reduction in the sensitivity to the direct-current J component of asymmetrical fault-currents, insensitivity to mechanical shocks, insensitivity to dirt, better calibration-characteristics, greater ease of construction .and adjustment, and, in

some cases, the possibility of.utilizing a single current-coil.

A further object of my invention is to provide a novel construction, and a novelprinciple of op'- eration, of a reactance-type relay, which may be either a resistance-responsive relay, a reactanceresponsive relay, or a modified-reactance relay which responds to both the line-reactance and the line-resistance, in any desired proportions.

With the foregoing and other objects in view, my invention consists in the structures, mechanisms, combinations, parts, systems, and methods, hereinafter described and claimed, and illustrated inthe accompanying drawing, wherein:

Figure 1 is a plan View of a high-speed induction-disk relay embodying certain features of my invention in the form of a directional or watt,- meter element with separate magnetic circuits for the current-responsive ilux and the voltageresponsive flux, parts being broken away to illustrate the construction;

Fig. 2 is a vertical sectional view on the plan indicated by the line II-II in Fig. 1;.

Fig. 3 is av diagrammatic development-view showing the multipolar construction spread out in a straight line, illustrating the magnetic ux- Datl'ls, and also illustrating the electrical connections for anembodiment of two of my disk-type relay-elements in a directionally controlled overcurrent relay;

Fig. 41s" a plan view, partly in horizontal section on the plane indicated by the line IVY-IV in Fig. 5, illustrating an embodiment of my invention in an induction-cylinder type;

Fig. 5 is an elevational View of the same cylinder-type relay, partly in section on the plane indicated by the line V--V in Fig: 4; and

Figs. 6 and 7 are diagrammatic views', similar to Fig. 3, illustrating applications of my invention to an impedance-relay and a reactance-relay, respectively. f

In Figs. 1 and 2, I show my invention as being embodied in an alternating-current electroresponsive relay, specifically a wattmeter or dlrectional element, utilizing a light-weight, rotatably mounted torque-producing member I0 which is mounted at right angles on a rotatable shaft II which is restrained by a spring I2 (Fig. 2), and which carries a movable contact-member I3 which is adapted to cooperate with stationary contacts I4 of a relay-controlled circuit I5. The essential feature of the torque-producing rotormember I0 is that it shall comprise a continuous,

Figs. 1 and 2, this torque-producing rotor-mem- I ber is shown in the form of a disk I0. In Figs. 4 and 5, it is shown in the form of a hollow cylinder III",

Cooperating with the rotor-disk I0, in the apparatus shown in Figs. 1 and 2,1is a stator-member comprising two magnetizable multipolar flux-producing means I'I and I8, disposed one above the rotor-member I0 (the shaft being vertical. and the other below said rotor-member, with airgaps I1' and I8' in between. Each of the multipolar flux-producing means Il and I8 extends substantially all the way around the circularly continuous` surface of the rotor-disk I0 or other sheet-like conducting-portion which constitutes the torque-producing member of my device. By the term multipolar, I mean a construction having more than one pole, and specifically, a construction having an even number of north and south poles, so that theterm will embrace a construction using either two, four, six, or more, poles on each side of the disk. In the particular form of embodiment shown in Fig. 1, there are four poles 2 0 and 2l, respectively, on each side of the disk I0. The poles 20 of the stator-structure I1 above the disk I0 are displaced in somethinglike vention. As shownv in Figs. 1, 2 and 3,'each of the pole-pieces 20 or 2| has a magnetizable, dat,

pole-face member 22 having its front face presented to the airgap I1' or I8', as the case may be. in the induction-disk form of construction shown in Figs. 1 and 2, each pole-face member 22 has a substantially segmental or sector shape, as clearly shown in Fig. 1, so that all four of the pole-face members of each of the magnet structures I1 and IB will extend all the way around the circumference or the disk, with certain spacings 23 between the radial edges of adjacent sector-shaped pole-face members 22, spacings 24 between the outer periphery of each pole-face member 22 and the outer periphery of the disk I0, and spacings 25 between the inner peripheries of the pole-tace members 22 and the shaft II. These spacings 23, 2l and 25 constitute portions or areas .of the disk II) which are not covered (through the airgap) by the pole-face members 22, and it will be noted that each poleface member 22 is entirely surrounded by an uncovered portion or area of the disk I0, as represented by said spacings/23, 24 and 25, thus providing a path for eddy-currents which are induced in the disk by the alternating magnetic flux ln therespective pole-face portions 22.

Each pole-piece comprises, in addition to the pole-face portion 22, a magnetizable pole-shank portion 28 which extends back from a small portion of the back face 21 of the pole-f ace member 22, extending away from the airgap. In the disktype relay shown in Figs. 1 and 2, these poleshank portions extend in directions parallel to the shaft II. An advantage of this form of construction is that the pole-shank portions 26 may Vbe in the form of iron or steel tubes, which may be split, as indicated at 28, to reduce eddy-current -losses in the magnetic circuit, thus avoiding the need for a laminated construction.

Each of the magnetic stator-structures I1 land Il, in Figs. 1 and 2, is completed by means of a magnetizable yoke-member shown at 2B and 30, respectively, These yoke-members join therear ends oi.' the shanks 26 of the pole-pieces of different polarities, thus providing' a return-flux path, Each of the pole-shank portions-26 is surrounded by a magnetizing coil 3i or' 32, the coils 3| of the upper magnetic structure I1 being pref erably the current-responsive coils, while the coils 32 of the lower magnetic structure I8 are preferably the voltage-responsive coils, the current-responsive coils being put on top, so that, under fault-conditions, when the current is excessive, the pulsatory repulsion existing between the currentenergized pole-pieces and the induction disk will press the disk more firmly down against the lower thrust-bearings,'which support the weight of the rotor-member at 34, thus avoiding lifting the rotor-member and causing chattering at this thrust-bearing. The 'respective multipolar structures I1 and I8 may be conveniently assembled by means of either magnetizable or non-magnetizable bolts extending through the several poleshank portions 26.

In Fig. 3, I have shown two of my inductiondisk structures, similar to that shown in Fig. 1, in a diagrammatic developed view in which the circumference of the disk isopened up and spread ut in a straight line to show the circumferential magnetic flux-paths. In Fig. 3, the upper relayelelnent 36 is an overcurrent relay having its contacts 31 in the relay-controlled circuit 33, while the lower relay-element 40 is a directional or wattmeter type of element, having its contacts Il in series with an energizing-circuit of the overcurrent relay 36, so that the overcurrent element may be energized or deenergized in response to the direction of current-flow, as determined by the directional element 4D.

In Fig. 3, the line-current is delivered to the current-coil circuit 3I of the lower or directional element 40, through the terminals I, I', in a circuit which includes an autotransformer 42 which supplies current both to the current-coi1s 3l and the voltage-type coils 32 of the upper, or overcurrent, element 3 6. The current which is supplied to the voltage-type coils 32 of the overcurrent element 36 is at a smaller currentLvalue and a high voltage-value thanA the current supplied to tl current-coils 3| of the same element 36, and tl. relative phases of the exciting-currents in the current and voltage-windings 3| and 32 of this overcurrent element 36 are controlled so that the two fluxes will be displaced, usually about 45 with respect to each other. To this end, I have shown a resistance 44 in series with the voltagetype coils 32 of the overcurrent element 36.

In Fig. 3, the line-voltage is supplied to the vo1tagecoils 32 of the directional element 4I), from the terminals E, E', a resistance 44 being again added to control the phase-relationships, to the end that maximum relay torque will occur when the current in the current-coils 3l of the relay lags the impressed voltage across the relay by approximately 45, so that the directionalrelay connection known as the connection may be used.

Reference to Fig. 3 will show that the currentresponsive ilux pI which flows up in one poleshank and down in the next adjacent pole-shank of the upper magnetic structure I1 of each relay-element, such as the directional element 4D, crosses both airgaps I1 and I8', and completes its circuit by a circumferential traversal of one of the pole-face portions 22 of the lower magnetic structure I8, the I magnetic flux-path being completed through the yoke-member 29 of the upper magnetizable structure I1. In like manner, the magnetic circuit of the voltage-responsive ux E is completed by a circumferential traversal of one of the p01ei`ace portions 22 ol the upper magnetic structure I1, after the flux has traversed both airgaps I1 and I8 two times, including also two passages through the thickness of t'ne disk IIJ as in the case of the flux (pli. The current-responsive magnetic ux pI of the upper structure I1 does not traverse any part of the lower structure I8 other than the pole-face portions 22 thereof, and, similarly, the voltage-responsive flux qiE of the lower structure I8 does not traverse any part of the upper structure I1 other than the pole-face portions 22. These poleface portions 22 are designed with suiliciently liberal cross-#sectional areas, with respect to fluxes flowing in a circumferential direction therein, so as to avoid saturation, as far as possible, and to provide a ready return-flux path for the flux which comes from the other magnetic statorstructure I8 or I1, as the case may be.

It is frequently desirable to deliberately provide for saturation of the magnetic iiux-path for the current-responsiveflux qsI; and it is one of the desirable features of my invention that this may be readily accomplished, by reason oi' the fact that the magnetic path for the current-responsive flux 431 is quite independent of the magnetic path for the voltage-responsive flux qbE, except for the lline-currents, and the bounce-producing effects of the excessive pulsating torques when the linecurrent is high, as under fault-conditions. In my structure, the saturation of the current-responsive flux-path may be readily accomplished by making the shank-portions 26 and/or the magnetic yoke portions 29 of the current-responsive magnetic structure of a suiiiciently reduced crosssection, as shown in Figs. 1, 2 and 3. To the same end, it is usually desirable to design the autotransformer 42, of Fig. 3, so that it will saturate, thus protecting the upper, or overcurrent, element 36 against excessive current-values.

A double operating-torque is produced in the'.

disk IIJ, or other continuous, sheet-like conducting-portion which constitutes the torque-producing member of my device. It will be noted, from Fig. 3, that the thickness of the disk Ill is crossed by two different flux-paths, one of them coming from the current-responsive magnetic structure I 1, and the other coming from the voltage-responsive magnetic structure I8; and each of these flux-paths is an alternating flux, producing eddycurrents in the portions of the disk surrounding' the respective segmental-shaped pole-faced members 22 of both the upper and lower field structures I'l and I8. The current-responsive eddycurrents in the disk I cooperate with the voltageresponsive flux 95E to produce a torque proportional to the product of the current times the voltage times a function of the angle between the two fluxes qSI and qSE. In like manner, the voltage-responsive eddy-currents in the disk I0 cooperate with the current-responsive ux pI to produce a torque proportional to the product of the current times the voltage times a function of the angle `between the two fluxes pI and E. These two torques combine to produce a strong operating-force or torque in a small space.

Reference to Fig. 1 will show that every possible square inch of surface of the disk I0, both top and bottom, is utilized to produce as much torque as possible, by the reactions between the eddycurrents in the disk and the respective fluxes in the upper and lower magnetic structures I'I and I8. It will be noted that the segmental-shaped pole-face portions 22 of both the upper magnetic g structure I'l and the lower magnetic structure I8 erably reduced if these spaces 23, 24 and 25 are.

made either too small or too large, meaning that either there is too much leakage-flux between poles and too little useful flux through the disk, or that the disk-inertia will be increased faster than the usefulflux, or the torque resulting is decreased speed. In a disk of 31A inches diameter, spacings of the order of 1A inch are satisfactory for the spacings 23, 24 and 25 in Fig. 1.

My disk-type construction, as shown in Figs.

' l, 2 and 3, has many advantages over other types of high-speed alternating-current relays known in the art. Important advantages include the provision of substantially separate flux-paths for the current-induced ux and the voltage-induced flux, thus largely minimizing stray-flux effects which have proven quite critical, and quite harmful to the sensitivity of many previous relays. The fact that the torque produced in my relay is substantially independent of the position of the moving element of the relay, or of the degree of separation ormovement of the contacts, such as I3--I4, 31 and 4I, is also an important feature, which makes my relay respond positively, with less sensitivity to dust or dirt, or to mechanical shocks received when the operating-force is just below the balance-point of the relay, and which also gives the relay a low dropout value, enabling it to readily return to its non-actuated position when the torque-producing conditions return to normal. The disk-construction, with plainly visible airgaps I'l' and I8 between the disk and the stator-structures, makes for ready inspection to detect the presence of lint or dirt bridging this airgap or clearance-space so as to facilitate keeping the relay in operating order. The compactness of the design, and the utilization of every possible square inch of disk-surface area on both sides of the disk, all make for large torques in a small space or volume, and with a small mass or inertia of the rotor-member, which means a very high speed of operation, ranking my relay foremost in performance, in the family of high-speed alternating-current relays.

As compared to previous induction-type relays, my relay, as shown in Figs. 1,- 2 and 3, presents the very great advantage of having the two fluxes which are out of phase with each other on opposite sides of the disk, with separate magneticcircuit structures provided for each, thus avoiding the leakage-flux and cross-ux troubles which are so prevalent in structures in which a single magnetizable stator-member providesy poles carrying both current-responsive and voltageresponsive fluxes. The separation of the currentand voltage-responsive uxes in two separate magnetic circuits also presents the advantage that any small stray-current torques may be readily balanced out by a slight rotating adjustment or turning of the lower multipolar assembly I8 with respect to the upper multipolar assembly I1.

As previously intimated, and as will be obvious from the descriptions and illustrations so far given, the broad principles of my invention, or

-some of them, are susceptible of general applications in other forms of embodiment than those shown in Figs. l, 2 and 3. Thus, the invention might `be applied to an overcurrent relay or an undervoltage relay, an impedance relay, a differential relay, a directional or wattmetric relay, a reactance or modified-reactance relay, or relays producing other effects or combinations of torques, either utilizing the upper multipolar magnetic structure I'l alone, with proper excitation, or (preferably) utilizing both the upper and lower structures, either in cooperation with each other, or to produce separate torques independently of each other. Some of these alternative forms of construction and embodiment of my invention will now be describedwith reference to the remaining figures of the drawing.

In Figs. 4 and 5, I show my invention applied to a constructiony in whichthe torque-producing rotor-member is in the form of a hollow cylinder III', which is supported, from one end, on a shaftcarried disk, spider, or other supporting-member llwhich extends out from the shaft and supports the cylinder IU in such mannerl that the rest of the cylinder. other than the small part which is in contact with the disk or end-closure 50, is an open-ended extending-portion extendlng in an axial direction in a spaced concentric relation with respect to the shaft. The cylinder In and the supporting disk 50 together constitute a cup-shaped member, so that the relay is sometimes referred to as a cylinder-type relay, sometimes, less accurately, as a cup-type relay, a1- though the torque is produced essentially only in the cylindrical part of the rotor-member.

In the cylinder-type relay shown in Figs. 4

structure 5I have pole-face members 52 which are preferably cylindrically curved, so as to present a uniform minimum airgap 52 with respect to the inner surface of the cylinder l', and these pole-face members 52 are preferably rectangularly shaped, so that all four pole-face members 52, together, will substantially cover, with airgap separation, the entire inner surface of the cylinder I0', except for the necessary spacings between the pole-face members 52, and the necessary endspaces where the cylinder ID extends axially beyond the ends of the pole-face members 52, in both directions, thus providing spaces on the cylindrical surface where the eddy-currents can flow in a manner which will be understood from the description in connection with the disk-type construction.

In Figs. 4 and 5, I utilize a single exciting-coil set in response to the curr'ent-responsive fluxes of the inner magnetizable stator-structure i, while the other set of eddy-currents is produced around the pole-face portions 59 of the outer stator-poles 51 in response to the voltage-responsive iiux of the stator-member; and these two setsof eddy-currents in therotor-cylinder IU' produce a double torque, responsive to the product of the two stator-fluxes, multiplied by a function of the phase-angle between them. The same advantages of compactness, low inertia, and the like, are obtained with my cylinder-type construction, as with my disk-type construction, plus the advantage of requiring only a single current-responsive coil, and the advantage of 'very great compactness of construction, which results from the cylindrical shape of the torqueproducing member and the use of an inner stator-field structure 5l as well as an outer stator fieldstructure 5i. Furthermore, during shortcircuits, when large vibrational forces act on the cylinder, they act radially on the cylinder, and

53 for the inner multipolar stator-member 5l, this coil 53 being preferably the current-energized coil, and being mounted on a magnetizable coremember 54 which is shown in the form of a piece of iron or steel tubing, which performs'the function of the previously described yoke-members. Alternate pole-face members 52 are secured to opposite ends oi the core-member 54, means of two spider-members 55 and 56, one at each end of the' core-member 54, constituting the several poleeshank portions to which alternate pcle-l`ace portions 52 are attached. 'I'hus, in 4 and 5, there are four pole-face portions 52; and these pole-face portions are connected in diametrical pairs to the respective spider-members 55 and 56 at opposite ends of the core-member 54, so that the pole-face members 52 are alternately north and south poles, at any given instant.

In Figs. 4 and 5, the outer magnetic statorstructure 5I is provided with four (or other plurality of) salient pole-pieces 51, corresponding to the number of the inner pole-pieces 52. The outer pole-pieces 51 project inwardly from a laminated yoke-structure 58, and which termim nate in rectangularly shaped, cylindrical-surfaced pole-face portions 59, which are spaced from the outer surface of the rotor-cylinder l0 by means of an airgap 6U. The shank-portions of the polepieces 51 carry coils 6I, which are preferably the voltage-energized coils of the relay.

The operation of the cylinder-type form of embodiment of my invention, as shown in Figs. 4 and 5, will be apparent, it is believed, from the foregoing description, particularly in View of the detailed explanation of the operation in connection with Figs. 1, 2 and 3. Two groups of eddycurrents are induced in the rotorwylinder IU', one

are balanced, so that they produce a minimum amount of vibration of the cylinder.

In Fig. 6, I illustrate how the general principles of my invention may be embodied in a relay of the differential or impedance type, wherein two opposite torques are to be compared, or combined in opposition to each other. In the case of the differential relay, these opposite torques may be produced by two diiierent currents, or by any other two diierent electrical quantities which are to be diiierentially compared. In the case of an impedance-relay, these two opposite torques are responsive, respectively, to the line-current and the line-voltage, so thatthe relay will respond when the ratio of the current tovoltage exceeds a predetermined amount, corresponding to a predetermined line-impedance.

In the form of embodiment of my invention which is shown in Fig. 6, the connections are shown for an impedance-relay having a shaft 6l carrying two spaced disks 65 and 66, both mounted on the sha-it at right angles thereto and in spaced parallel relation to each other. 'I'he shaft $4 is shown as a vertical shaft. The upper disk 65 is surmounted by an upper magnetizable statorstructure l1, which is spaced from the upper disk E5 by an airgap I1'. Below the lower disk B6, there is provided a second magnetizable statorstructure I8, which is spaced from the lower disk 66 by an airgap i8'. Between the two disks 65 and G6 is disposed a magnetizable stator memrber 61 which is spaced from ,the two disks by air gaps 65 and 66', respectively. The central magnetizable stator-member 61 is preferably of suiicient cross-sectional area, for circumferentially rotating fluxes, to avoid saturation in the manner previously described for the pole-face portions 22 in Fig. 3.

In Fig. 6, it is 'necessary to utilize means for producing a rotatably progressing iiux in the successive pole-face portions 22 of both the upper and lower magnetizablestator-members I1 and I 8, and to this end I show alternate poles as being provided with lag-rings 68. In this construction, it is necessary to utilize two north poles followed by two south poles, at any instant, so that the minimum possible number of poles is four, for each of the two multipolar magnetizable structures l1" and I8". The lag-rings 68 produce a lagging of the ilux therein, thus producing the well-known rotating-flux eiect. 'I'he centrally disposed magnetizable stator-member 61, between the two disks l5 and `6B, serves simply velops a torque proportional to the square ofA the flux in the lower stator magnet-structure I8", and these two torques can be combined,in opposition to one another, to constitute the operating-torque of the relay. n

In order to illustrate that' the current-responsive magnet-structure does not need to be above the disk-structure, although such disposition is advantageous, as described in connection with Figs. 1, 2 and 3, I have shown, in Fig. 6, a method of construction in which the lower magnet-structure I8" is excited in response to the line-current I-I, receiving its energization through an adjustable autotransformer 1D, the adjustment of which may be iinely adjusted by a Vernier-potentiometer or variable-resistance II connected across the variable part of the autotransformer 10. 'Ihe upper held-magnet structure I1" in Fig. 6 is energized-,in response to the line-voltage, .as indicated 'by the terminals E and E. The relay of Fig. 6 thus develops an operating-torque responsive tov the square of the value which can be predetermined by adjusting the phase-angle of the impedance 'I6-"I1, and 0 line-current, in the lower disk 66, and a restraining-torque responsive to the square of the line-voltage, in the upper disk 65, thus constituting an impedance-relay.

In Fig. 7, I have shown my invention embodied in a novel type of reactance-relay or modiedreactance relay. structurally, the relay is, or may be, similar to that which is shown in any i of Figs. l1 to 5. It has been represented diagram-l coils 3| and 32'. The voltage-coils 32 are enery gized from the line-voltage E-,E' through a phase-adjusting and magnitude-adjusting impedance, shown as comprising a variable capacitor 'I6 and a serially connected variable resistance TI.

In the adjustment and operation of the relay shown in Fig. 7, the relative phases and proportionality-ratios of the current-responsive flux produced in the upper magnet I'I and the voltageresponsive flux-component produced in the lower magnet I B may beadjusted by the autotransformer 'I5 and the variable impedance I6- 11. The voltage-coils 32 act as short-crcuited turns on the poles of lthe lower-magnet frame I8, with respect to the current-responsive iiux-component in these same poles, thus producing a lagging phase-angle of this current-responsive flux-component` with respect to the unshaded currentresponsive flux in the poles of the upper-magnet frame I'I, producing-a torque equal to K12, I being the line-current. and K being a constant. The purely current-responsive iiux in the upper magnet-frame I'I cooperates" with the Voltageresponsive iiux-component in the lower-magnet frame I8 to produce a torque equal to kEI cos (ei- 6), where E is the line-voltage, 7c is a constant, a isr a iixed angle of any predetermined is the phase-angle between line-current and the line-voltage. 'I'here is no torque produced by the,

product of the fluxes produced by the current and voltage-coils 32 and 32 on the lower poles, since they are not displaced in space with respect-to each other. If the current-responsive torque is an ,operating-torque, the voltage-current-angleresponsive torque will be a restraining torque, at least for certain angles.

The total torque T produced in the relay may be Written T=KI2-IEI cos (ol-0) il) If the fixed angular displacement a is the torque becomes Ty: KIZ-kEI sin e positive if the line-reactance X is less than K/k, and the torque is negative if X is greater than K/c, the relay being adjusted so that itwill respond to a positive torque, and fall back, or fail to respond, in the presence of a negative torque.

If the predetermined xed angle a is zero, the torque becomes p TFKILICEI cos o where R is .the line-resistance. The relay thus becomes a resistance-responsive relay.

For intermediate values of the fixed angle a, the relay of Fig. 'I becomes a modined-reactance relay, responsive to both the line-reactance X and the line-resistance R, developing a torque,

T= KIZ-iEI cos (cz-49) v '=KI2-kEI (cos a cos-6+sin a sin 0) I' to a limiting line-resistance (without reactance) of esc -R cot a This modied-reactance response. as indicated sec a-R tan a in Equation 4, is thus a straight-line response, l

whereas the response of the previously known modiiied-reactance relay was an arc of a circle, as set forth in the Lewis patent, 1,967,093, granted July 17, 1934, and assigned to the Westinghouse Eelctric and Manufacturing Company.

It is obvious thatA this new straight-line modined-reactance relay, either in the general case, or in the limiting cases in which the relay responds to pure reactance or to pure resistance, may be carried out by any electroresponsive means which produces the torques set forth in Equations 2, 3, and 4, that is, any apparatus.

which produces an operating-force responsive to the square of a single-phase current, and a restraining-force responsive to'the product of said current, times a single-phase voltage, times the sine (or cosine) of an angle equal to a constant angle plus or minus the phase-angle between the current and the voltage to which the device responds. It is obviously not necessary, so far as the result is concerned, to use the particular means which I havesshown, for producing these two opposing torques, although my novel form of relay, as shown, Vprovides an excellent medium for carrying out this novel idea respecting a modiiled-reactance response.

In Fig. 7, it will be noted that an essential ccndition concerning the operation of the relay is that the current-responsive finir-component in the lower magnet-frame I8 shall be out of phase with the current-responsive flux-component in the upper magnet-frame i1; and that the voltage-responsive flux in the lower magnet-frame I8 shall bear a predetermined phase-relationship, such as (ar-), with respect to 'the currentresponsive 4flux in the upper magnet-frame i.. .Any means for bringing about, su.' ncntroiiing, these several phase-relationships will be satisfactory, including, for example, the currentshifting means shown in connection with the overcurrent element 36 of Fig, 3; and I desire Fig. 'l to be understood, in a generic sense, as symbolic of any suitable means for providing the stated phase-relationships between the several fiuxes.

While I have described my invention, and explained its principles of operation, in connection with several different specific forms of embodiment, I wish it to be understood that my invention is not altogether limited thereto, as many changes and adaptations will be obvious to those skilled in the art. I desire, therefore, that the appended claims shall be accorded the broadest construction consistent with their language.

I claim as my invention:

1. An alternating-current electro-responsive device comprising a light-weight, rotatabli7 mounted, torque-producing member comprising a light-weight, substantially non-magnetizable, continuous, sheet-like, conducting-portion having a surface which returns circularly on itself, and a stator-member comprising two magnetizable multipolar flux-producing means disposed one' on either side of said rotor-member, with airgapg in between, each multipolar fiux-producing means comprising a set of salient magnetizable pole-pieces having pole-face portions sep-` 'thing like a quadrature space-relation with respect to thepoles of the other, whereby the flux from or to each pole of each ot the multipolar flux-producing means crosses both airgaps and the sheet-like conducting-portion and flows circumferentially in the pole-face portions of two poles of the other multipolar flux-producing means.

2. An alternating-current wattmeter-type electro-responsive device comprising a light-weight, rotatably mounted, substantially non-magnetizable, continuous, sheet-like, conducting-portion having a surface which returns circularly on itself, and a stator-member comprising tivo magnetizable multipolar flux-producing means disposed one on either side of said sheet-like conducting-portion with airgaps in between, each multipolar flux-producing means comprising a set of salient pole-pieces of alternately opposite polarities succeeding one another and extending all the way around a complete circle, the poles of one multipolar linx-producing means being dis placed in something like a quadrature spacerelation with respect to the poles of the other, exciting-winding means operatively associated with the respective multipolar flux-producing means for producing magnetic iiuxes in the salient pole-pieces, and two single-phase terminal-means, each adapted to be energized for energizing the entire exciting-Winding means for the entire sets of pole-pieces of one of said multipolar flux-producing means, whereby a torque is produced having a magnitude and a clirection dependent upon the product ci' the two magnetic fluxes times a. function of the phaseangle between them.

3. An alternating-current wattmeter-type electro-responsive device comprising a light-weight, rotatably mounted, substantially non-magnetizable, continuous, sheet-like, conducting-portion having a surface which returns circularly on itself, and a stator-member comprising two magnetizable multipolar iiux-producing means disposed one on either side of said sheet-like conducting-portion with airgaps in between, each multipolar flux-producing means comprising a set of salient pole-pieces of alternately opposite polarities succeeding one another and extending all the way around a complete circle, each polepiece comprising a magnetizable, pole-face member having its front face presented to the airgap of its multipolar Eux-producing means, and a magnetizable pole-shank portion extending back from a small portion of the back face of the poleface member away from the airgap, and each multipolar flux-produc ing means having a magnetizable yoke-member providing a return-ilux path between the rear ends of the shanks of all of the pole-pieces, the front faces of the plurality of pole-face members of each multipolar `flux-producing means being of such shape and area as to cover (through the airgap) substantially the entire available eddy-current-producing and eiective torque-producing surface oi said sheet-like conducting-portion, with uncovered portions of adequate size. but of a size only corresponding to certainnecessary rotatably shiftable eddy-current paths in the sheet-like conducting-portion, the poles of one multipolar flux-producing means being displaced in something like a quadrature space-relation with respect to the poles of the other, exciting-Winding lmeans operatively associated with the respective multipolar flux-producing means for producing magnetic fluxes in the salient pole-pieces, and

'two single-phase terminal-means, each adapted to be energized for energizing the entire excitingwinding means for the entire set of pole-pieces of one of said multipolar flux-producing means, whereby a torque is produced having a magnitude and a direction dependent upon the product of the two magnetic fluxes times a function of the phase-angle between them, the effective cross-sectional areas of the pole-face members of both of said multipolar flux-producing means, for circumferentially moving fluxes therein, being ample to avoid substantial saturation during lo maximum-flux operating-conditions. I

4. The invention asdeiined in claim 3, characterized by the portion of the magnetic fluxpath including the shanks and yoke-member of at least one of said multipolar flux-producing means including, somewhere, a suflicient crosssectional restriction to produce substantial saturation under the samemaximum-flux operatingconditions which produce no substantial saturation for circumferentially moving fluxes in the pole-face members.

5. An alternating-current electro-responsive device comprising a rotatably mounted shaft, a light-weight disk of electrically conducting material mounted atright angles on the shaft, and a stator-member comprising a magnetizable multipolar flux-producing means disposed on one side of said disk, with an airgap in between, said multipolar flux-producing means comprising a plurality of salient pole-pieces of more than one polarity, each salient pole-piece having a magnetizable, nat, substantially sector-shaped, poleface member having its front face presented to said airgap, the front faces of the plurality of pole-face members of said multipolar iiux-producing means being of such area as to cover (through the airgap) substantially the entire available eddy-current-producing and effective torque-producing surface of said disk, with uncovered disk-portions between the radial edges of adjacent sector-shaped pole-face members, between the outer periphery of each sectorshaped pole-face member and .the outer periphery of the disk, and between the inner peripheryof each sector-shaped pole-face member and rth'e 315 inner periphery of the disk, said uncovered diskportions providing a rotatably shiftable disk'- path for eddy-currents surrounding each of the sector-shaped pole-face members, said eddycurrent disk-paths being of cross-sectional areas which are sufficient at each point, but no more than reasonably suicient, to accommodate the eddy-current flow without excessive resistancelosses at any point, the successive pole-face members extending all the way around a complete '55 circle. l

6. The invention as defined in claim 5, characterized by said stator-member comprising two magnetizable multipolar flux-producing means disposed on opposite sides of the disk, with airgaps in between, each magnetizable flux-producing means being substantially of the nature set forth in claim 5, with the pole-face members of the respective multipolar iiux-producing means circumferentially staggered with reference to o5` each other, whereby the eddy-currents induced in the disk by lthe fluxes from the several poleface members produce a torque having a magnitude and a direction dependent upon the product of the fluxes in the respective multipolar disposed on opposite sides of the disk, with air- 4 gaps in between, each magnetizable flux-producf response coils.

8. An alternating-current electro-responsive device comprising a rotatably mounted shaft, a light-weight sheet-like, hollow cylinder of substantially non-magnetizable, electrically conducting material, a supporting-member extending out from the shaft for supporting the cylinder on thek shaft in such manner that the cylinder has an open-ended extending-portion extending Kin an axial direction from said supporting-member and in a spaced concentric relation with respect to the shaft, and a stator-member comprising `an vseveral pole-shank portions so as to cause different pole-face members, at displaced points all the way around the circumference, to be magnetized from different ends of the core-member, and exciting-winding means on the core-member for exciting all of the poles of said inner multipolar flux-producing means; said stator-member also comprising an outer magnetizable multipolar flux-producing means encircling the open-ended extending-portion of the cylinder, with an airgap in between, the inner and outer airgaps being on opposite sides of said open-ended extendingportion of the cylinder, said outer multipolar flux-producing means comprising a plurality of salient pole-piecesof more than one polarity, each pole-piece comprising. a magnetizable, substantially rectangular-shaped, pole-face member having its front face presented to said airgap, and a magnetizable pole-shank portion extending in a y substantially radial direction back from the poleface member away from thegairgap, and a magnetizable yoke-member providing a return-flux path between the rear ends of the shanks 0f the pole-pieces, the front faces of the plurality of pole-face members' of said'outer multipolar nuxproducing means extending all the way around the circumference in circumferentially stag-v gered relation with respect to the pole-face members ofthe inner 4multipolar ux-producing means, .whereby the eddy-currents induced in said open-ended extending portion of the cylinder bythe fluxes fromthe several pole-face members produce a torque having a magnitude `and a direction dependent 11i-0n the product of the fluxes in the respective multipolar ilux-producing means, multiplied by a function of the phase-angle between them, and exciting-winding coils on the respective pole-Shanks of the outer multipolar flux-producing means;

9. An alternating-current electro-responsive device comprising a light-Weight, rotatably mounted, torque-producing member comprising a light-weight, continuous, sheet-like, conducting-portion having a surface which returns circularly on itself, and a stator-member comprising a magnetizable multipolar flux-producing means disposed on one side of said sheet-like conducting-portion, with an airgap in between, said multipolar flux-producing means comprising a set of salient pole-pieces of more than one polarity, each pole-piece comprising a magnetizable, pole-face member having its front face presented to said airgap and a magnetizable poleshank portion extending back from a small portion of the back face of the pole face member away from the airgap, and a magnetizable yokemember providing a return-flux path between the rear ends of the shanks of all of the polepieces, the front faces of the plurality of poleface members of said multipolar flux-producing means being of such shape and area as to cover (through the airgap) substantially the entire available eddy-current-producing and effective torque-producing surface of said sheet-like conducting-portion, with uncovered portions of the sheet-like conducting-portion of adequate size but of a size corresponding to certain necessary rotatable shiftable eddy-current paths in' said sheet-like conducting-portion, the successive pole-face members extending all the way around a complete circle, means for producing magnetic iluxes in the respective salient pole-pieces, a common electric-circuit terminal-means adapted to be energized for energizing the means for producing the magnetic fluxes with a variable singlephase electrical quantity, and dephasing-means associated with some of said pole-pieces for causing the flux therein to differ, in phase, from the flux in some other pole-pieces, whereby a rotating flux-Held is produced, said stator-member further comprising a second magnetizable-fluxcarrying member disposed on the'opposite side of said sheet-like conducting-portion, with an airgap in between, said second magnetizable nuxcarrying member providing a iiux-path for circumferentially moving fiuxes between pole-pieces of different polaritles. v

10. An alternating-current electro-responsive device having a double rotatably mounted torqueproducing member comprising two light-weight, continuous, sheet-like conducting-portions held in iixedly and uniformly spaced relation with respect to each other; and a stator-member comprising two magnetizable multipolar ilux-producing means disposed on opposite sides of the double rotatably mounted torque-producing member, each of said multipolar ilux-producing means being associated1 with airgap separation, with a different one of said two conducting-portions of the rotatably mounted member; each of said multipolar flux-producing means comprising a set or salient pole-pieces o1' more than one polarity, each pole-piece comprising a magnetizable, pole-face member having its front face presented to the airgap and a magnetizable poleshank portion extending back from a small portion of the back face of the pole face member away from the airgap, and a magnetizable yokemember Vproviding av return-iiux .path between the rear ends of the Shanks oi' all of the polepieces, the front faces of the plurality of poleface members of said multipolar flux-producing means being of such shape and area as to cover (through the airgap) substantially the entire available eddy-current-producing and effective torque-producing surface of the associated sheetlike conducting-portion, with uncovered portions of the sheet-like conducting-portion of adequate size but of a size corresponding t0 certain necessary rotatably shiftable eddy-current paths in said sheet-like conducting-portion, the successive pole-face members extending all the way around a complete circle; said stator-member further comprising an intermediate magnetizable fluxcarrying means disposed between the two conducting-portions, with airgaps in between; exciting-winding means operatively associated with the respective multipolar flux-producing means for producing rotating magnetic iluxes in the respective sets of pole-pieces, andterminal-means adapted to be electrically energized for variably energizing the exciting-winding means,

l1. An alternating-current wattmeter-type electro-responsive device comprising a light-weight, rotatably mounted, substantially non-magnetizable, continuous, sheet-like, conducting-portion having a surface which returns circularly on itself, and a stator-member comprising two magnetlzable multipolar mix-producing means disposed one on either side of said sheet-like conductingportion with airgaps in between, each multipolar ilux-producing means comprising a set of salient pole-pieces of alternately opposite polarities succeeding one another and extending all the way around a complete circle, the poles of one multipolar flux-producing means being displaced in something like a quadrature space-relation with respect to the poles of the other, exciting-winding means operatively associated with one of the multlpol'ar flux-producing means for producing single-phase current-responsive magnetic iluxes in the several salient pole-pieces of that multipolar iiuX-producing means, and exciting-winding means operatively associated with the other multipolar flux-producing means for producing singlevphase current and voltage responsive magnetic fluxes in the several salient pole-pieces of that multipolar flux-producing means; the

- current-responsive component of the liux in the last-mentioned multipolar flux-producing means being out o1 phasewith the iiux in the first-mentioned multipolar linx-producing means; and the voltage-responsive component of the flux in the second mentioned multipolar flux producing means being displaced from the flux in the rstmentioned multipolar Eux-producing means by a phase-angle equal to a constant angle plus or minus'the phase-angle between the current and the voltage to which the device responds.

12. The invention as defined in claim 1l, characterized by said constant angle being such that the torque produced by the current-responsive ilux in the ilrst flux-producing means and the voltage-responsive flux-component in the second flux-producing means is substantially proportional to the current. times the voltage times the sine portion having asurface which returns circular-ly on itself. and a stator-member comprising two magnetizable multipolar flux-producing means disposed one on either side of said sheet-like conducting-portion with airgaps in between, each multipolar flux-producing means comprising a set of salient pole-pieces of alternately opposite polarities succeeding one another and extending all the way around a complete circle, the poles of one multipolar linx-producing means being displaced in something like a quadrature space-relation with respect to the poles of the other, exciting-winding means operatively associated ywith one of the multipolar flux-producing means for producing single-phase current-responsive magnetic fluxes in the several salient pole-pieces of that multipolar linx-producing means, and exciting-winding means operatively associated with the other multipolar linx-producing means for producing single-phase current-and-voltage-responsive magnetic fluxes in the several salient pole-pieces of that multipolar flux-producing means.

le. A single-phase wattrneter-type electro-responsive device having a stator-member comprising a magnetizable structure including a plurality oi salient pole-pieces extending around a. complete circle at circumferentially spaced points, exciting-winding means for causing alternate polepieces to be traversed by different ones of two single-phase magnetic fluxes susceptible of having a difference in time-phase therebetween, and a rotor-member having conducting-means disposed in the airgap in front of the several salient polepieces in such manner as to have a pole-encircling secondary-current circuit surrounding each pole-piece, with current induced therein by the magnetic ux of said pole-piece, each secondary-current circuit having a substantial proportion of two sides of its current-path lying in good torque-producing position in the portion of the airgap in front of the two adjacent polepieces lying on opposite sides of the current-inducing pole-piece, whereby a rotor-torque is produced, proportional to the product of ^the two single-phase fluxes multiplied by a function ofV the time-phase between them.

15. The invention as defined in claim 14, characterized by the conducting-means of said rotormember comprising a continuous, sheet-like conducting-portion having a surface which returns circularly on itself.

16. The invention as defined in. claim 14, characterized by the conducting-means of said rotormember comprising a disk of electrically conducting material mounted at right angles on the rtor-shaft.

17. The invention as defined in claim 14, characterized by the conducting-means of said rotormember comprising a sheet-like hollow cylinder of electrically conducting material mounted for rotationabout its axis.

18. A single-phase wattmeter-type electro-responsive device adapted for use on an alternating-current system and having a stator-member including two flux-producing winding-means for producing two single-phase magnetic fluxes susceptible of having a difference in time-phase therebetween, and a rotor-member so disposed as to produce a torque which is proportional to the product of the two single-phase fluxes multiplied by a function of the time-phase between them, in combination with electric energizingmeans for energizing the two ux-producing ties derived from said alternating-current system in such manner that at least one of said fluxes is responsive to the vectorial sum of an alterhating-current function or" a line-current and an alternating-current function of a line-voltage.

19. A single-phase wattmeter-type electro-responsive device adapted for use on an alternating-current system and having a stator-member including two flux-producing winding-means for producing two single-phase magnetic uxes susceptible of having a diierence' in time-phasey therebetween, and a rotor-member so disposed as to produce a torque which is proportional to the .product of the two single-phase fluxes multiplied by a function of the-time-phase between them, in combination with electric energizingmeans for energizing the two flux-producing winding-means in response to electrical quantities derived from said alternating-current system in such manner that one of said fluxes is responsive to the vectorial sum of an alternatingcurrent function of a line-current and an alterhating-current function of a line-voltage, and in. such manner that the other of said uxes is'responsive to a line-current.

20. A singleephase wattmeter-typey electro-re- Y sponsive device adapted for use on an alternating-current system and having a stator-member including two ux-producing winding-means for producing two single-phase magnetic uxes susceptible of having a diierence in time-phase therebetween, and a rotor-member so disposed as to produce a torque which is proportional to the product of the two vsingle-phase fluxes multiplied by a function of the time-phase between them, in combination with electric energizing-means for energizing the two flux-producing winding-means in response to electrical quantities derived from said alternating-current system in such manner that one` of said fluxes is responsive to the vectorial sum' of an alternating-current function of a line-current and an alternating-current function of a line-voltage, and in such manner that the other of said fluxes is responsive to the same line-current which combines with the line-voltage to control the first-mentioned flux.

2l. The invention as defined in claim l, characterized by the spacings between the pole-face portions of each multlpolar flux-producing means being of `the order of 1A inch, and the spacing between the outer edge of the entire assembly of pole-face portions and the outer edge of the sheet-like, rotatably mounted conducting-portion being also of the order of 1/4 inch.

windini-means in response to electrical Quanti- 22. The invention as defined in claim 2, characterized by the spacings between the pole-face 4portions of each multipolar flux-producing means being of the order of inch, and the spacing between the outer edge of the entire assembly of pole-face portions and the outer edge of the sheet-like, rotatably mounted conducting-portion being also of the order of A inch.

23. The invention as defined in claim 3, characterized by the spacings between the pole-face portions of each multipolar flux-producing means being o1' the order of An inch, and the spacing between the outer edge of the entire assembly of pole-face portions and the outer edge of the sheet-like, rotatably mounted conducting-portion being also of the order of 1/4 inch.

BERT V. HOARD. 

